Well drilling tool



July 2, 1940- T. A. cRElGH-roN r:r Al. 2,206,222

wnLL DRILLING Toor. l'

Filed July 24. 1939 Patented July 2, 1940 WELL DRILLING TOOL Thomas A. Creighton and Thomas E. McMahan, Long Beach, Calif., assignors oi.' one-third to Mmm n. wright, Los Angeles, can.

Application July 24, 1939, serial No. 286,213 l. (01.25541) Claims.

This invention relates to well drilling tools and relates more particularly to well bits for use in the rotary method of well drilling. A general object oi' this invention is to provide a practical,

i eilective, rotary well drilling tool that facilitates the testing and surveying of the well as the well drilling operations progress.

This application is a continuation in part o1' our co-pending application, Serial No. 214,234.

l0 entitled ,Well bit, now Patent No. 2,179,010,

granted Nov. 7, 1939.

Rotary well drilling bits have been introduced having openings for receiving surveying instruments, and the like, to permit the making of well u surveys and well tests without the necessity of withdrawing the bits and drilling strings from the wells. A bit of the class just mentioned usually has a central vertical opening of substantial diameter for passing the surveying instrument. It is necessary to arrange a removable core receiving barrel or a removable core destroying device in thisopening to cut away the core as the'drilling progresses, so that the surveying instrument may be entered through the opening in the bit. In employing a bit of the class referred to it is necessary to remove the core barrel or the core destroying device from the blt when a survey iis to be made. Following the sury veying operation it is necessary to lower or run the core barrel or core destroying device down through the drilling string to its position in the bit. These operations are time consuming and, therefore, expensive.

Another object of this invention is to provide a rotary well drilling bit having a central longitudinal opening for the reception of surveying tools and other objects and embodying a core cutting means that is retractable to allow a surveying instrument or other object to be received in or o passed through the said opening when the tool is in the well.

Another object of this invention is to provide a drilling tool o! the character mentioned in which the retractable core cutting means need not be withdrawn or removed from the bit when the bit is in the well and may constitute a permanent element of the bit.

Another object of this invention is to provide 50 adrilling bit of the character mentioned embodying a core cutting means that is automatil cally retracted by a surveying tool, sample taker. or other object run through the bit and that is automatically restored 4to its active core cutting 55 condition upon the withdrawal of the tool or object so that the drilling operations may be immediately resumed. v

Another object of this invention is to provide a well bit of the character mentioned embodying simple, dependablecore cutting elements that 5 l bodily shift between their retracted positions and their active positions.

A further object of the invention is to provide a well bit of the character mentioned that requires no special handling or control, -being 0p- 10 erable in the same `manner as a typical rotary well drilling bit. Y The various objects and features of our lnvention will be fully understood from the following detailed description of typical preferred i6 forms and applications of the invention, throughout lwhich description reference is made to the accompanying drawing, in which:I

Fig. 1 is a side elevation of a rotary well blt embodying the present invention. Fig. 2 is an 20 enlarged bottom view of the bit shown in Fig. 1. Fig. 3 is an emerged fragmentary vertical detailed sectional view taken as indicated by line 3 3 on Fig. 1. Fig. 4 is a view similar to Fig. 3 showing another form of the invention, and Fig. 25 5 is a fragmentary view similar to Fig. 3 showing still another form of the invention.

The present invention may be embodied in well drilling bits of various types and constructions. In the following detailed description we will de- 30 scribe three forms of the invention embodied in drag type rotary bits. It is to be understood that the invention is not to be construed 4as limited or restricted to the speciic` iorms or applications herein disclosed. Further, it is to be understood 35 that where reference is made herein to surveying instruments, sample takers, surveying operations and sample taking operations, it is contemplated that such references are to be construed as meaning the various instruments, tools and operationsthat may be eniployed for determining, testing and recording the `various conditions in a well, such as temperature conditions,` directional conditions, earth formation conditions, pressure conditions, etc.

`The well bit of the present invention illustrated in Figs. 1, 2 and 3 of the drawing, may be said to comprise, generally, a bit body I0 having a central longitudinal opening Il for receiving or passing an object, cutting means I2 on 'the 50 bodyv l0 for cutting the well bore to gauge and retractable means I3 for cutting or breaking away the central portion of the earth formation. The body ill of the bit illustrated in Figs. 1 to 3, inclusive, of the drawing, is'in the nature 55 -.on the lower end portion of the body of an elongate stem or shank. The lower major portion of the bit body I0 is cylindrical and of uniform diameter while the upper portion Ill of. the body is enlarged and tapered downwardly and inwardly. Means is provided at the upper end of the body III for facilitating its connection with a well drillingstring. In the typical illustrated a tapered screw threaded socket I5 is provided in the upper portion of the body Il to receive a correspondingly shaped pin on 'the' lower end of the string. The opening II extends downwardly through the body III from the socket I5 to the lower end of the body. The opening I I serves to handle or conduct the circu-` lation fluid and is proportioned to receive or pass the surveying instrument. In accordance with the invention the opening II has a substantial diameter to readily receive or pass the surveying instrument. Means are provided in the body ID t'o assist in locating and supporting the surveying instrument. An annular flange I6 is provided on the wall of the opening Il. The ange I6 is spaced below the socket I5. The lower portion/ of the opening II is reduced in diameter to receive the instrument with suitable clearance an to form an'upwardly facing shoulder. The flange I6 and the reduced lower portion of the opening II serve to center and locate the surveying instrument in the body III of the blt.y

The cutting means I2 is provided to cut away the earth formation and form the well bore. The present invention is not primarily concerned with the character of the cutting means embodied in the blt andcontemplates the employment of cutting means and elements of various natures. In the form/ of the invention being described the cutting means I2 includes two cutting blades I1 Ill and a, set of spaced cutting blades I3 on the upper enlarged body portion I4. The cutting blades I1 may be termed pilot blades and operate to form an annular cut in the earth formation to receive the lower portion of the shank I0 with suitable clearance. The blades I1 project downwardly and outwardly from the lower end of the body I0 and have upwardly and inwardly inclined Vlower cutting edges and substantially vertical strument A thro to provide notches 2l in the lower end reaming edges. The inner edges of the blades I1 are clear of or aligned with the wall of the opening II to permit the passage of the surveying iniigh the opening. The lower` end portion of the lbody III may be provided with stabilizing blades lI9. The blades* I9 project downwardly and outwardly from the lower end of the body I0 and have quite broad outer surfaces 29` adapted to cooperate with the outer wall of the cut made by the blades I1 to assist in stabilizing the bit. It will be observed that the pilot blades I1 operate to form an annular cut and leave a central portion or core of earth formation in line with the opening II. It is preferred of the body III to communicate with the opening II. The notches 2l are provided to permit the free lateral discharge of fluid from the opening Il I and are preferably arranged in front of the blades I1 with. respect to the direction of rotation of the bit. l

4The upper blades It are the reaming or bore enlarging blades of the'cutting means l2. The blades I8 project downwardly and outwardly from the enlarged tapered body portion- I4. The lower edges 22 of the cutting blades Il slope downwardly and outwardly and the outer edges or reaming edges 23 of the blades I8 may be substantially vertical. The blades I8 are operable to enlarge the Well bore to receive the drilling string with substantial clearance and thus provide for the return ilow of circulation fluid through theA well bore.

The means I3 is an important feature of the invention. Themeans I3 operates to remove or cut away the core of earth formation and in accordance with the invention is retractable to allow a surveying instrument, sample taker, or other object to be received in or pass through the body opening II. The means` I3 includes one or more shiftable. core breaking or core cutting dogs 24. In the form of the invention illustrated in Figs. l, 2 and 3 there are .two dogs 24. It is preferred to locate the core breaking means I3 adjacent the lower end of the bit body I0 and in v the construction illustrated the means I3 is provided below the shoulder 9 on the wall of the opening II. The body III is constructed or formed to accommodate the means I3. Two substantially diametrically opposite slots or openings 26 are provided in the lower portion of the body III. The openings 26 may be positioned as found most practical. In the case illustrated the openings' 26 are adjacent the forward sides of the Iguide blades I9 where the body wall has substantial thickness. The openings 29 are vertically elongated and have at parallel side walls. The upper and lower walls of the openings 26 are straight and substantially parallel. The outer sides of the openings 26 are open to the well bore and the inner sides of the openings are in communication with the longitudinal body opening Il.

A core cutting dog 24 is provided in each lateral opening 26. The dogs 24 may be flat plate-like parts whose opposite side surfaces shiftably bear on the side walls of the openings 26. In accordance 'with the invention the dogs 24 are adapted to bodily shift in their respective openings 26. The side surfaces of the dogs 24 shiftably bear on the side walls of the openings 29 and the upper edges of the dogs are adapted'to bear against the upper walls of the openings. The dogs 24 are guided for movement between the projecting active positions, illustrated, and retracted positions where they are clear of the opening I I. Each dog 24 is provided with a downwardly and outwardly sloping slot 21 receiving or passing a pin 28 carried by the body I9. The pins 28 are nat-sided to cooperate with the side walls of the-slots 21 and are fixed in openings in the body I0 to extend through the openings 29 and theslots 21. The cooperation of the slots 55 21 and the pins 29 guides the dogs 24 for downward and outward movement from their,v active positions to their retracted positions and the en'` gagement of the pins with the ends of the slots limits the travel of the dogs. r The upper inner cornersl of the dogs 24 are bevelled off to have, downwardly and inwardly sloping faces 29. The faces 29 are engageable by a surveying tool,

l sample taker, or other object run down through the opening II and the engagement of the object 65 with the faces 2 9 causes downward and outward shifting of the dogs 24.

The lower edges 30 of the dogs 24 are adapted to cooperate with the core of earth formation to /cut the same away. The cutting edges 3l may 'l0 be straight and horizontal, as'illustrated, and if desired or necessary may be sharpened. As best' illustratedI in Fig. 3 of the drawing vthe dogs 24 may be proportioned to have their inner edges immediately adiacent'the central vertical axis 1i' `against the upper walls of the openings 26`there are spaces of substantial capacity under the dogs allowing free circulation of fluid through the openings 26.

'I'he invention includes means for returning the dogs 24 to their active projecting positions following the withdrawal of the surveying tool or object from the opening II. A spring means is associated with each dog 24 tolurge the dog inwardly to its active cutting position. In the construction illustrated leaf springs 3| are secured to the body I0 by screws 32 and extend into the openings 26 forengagement with the dogs 24. The springs 3| slope downwardly and inwardly and have cooperation with the lower rear corners of the dogs 24. 'Ihe springs 3| normally hold the dogs 24 in the positions illustrated in the drawing where they are operable to cut away the core. The springs 3| are yieldable to permit the downward and outward retraction of the dogs 24 by an object lowered through the opening Il.

In the operation of the bit illustrated inFigs. l, 2 and 3 of the drawing the body lli is connected with the lower end of a rotary well drilling string and the string is rotated and fed downwardly in the well in the usual manner. 'I'he cutting blades I7 assisted by the blades I9 make' an annular cut inwthe bottom of the well leaving a central upstanding core of earth formation. The blades IB enlarge this annular cut to form a. bore which freely receives the drilling string. `The upstanding core is destroyed or drilled away by the dogs 24. 'I'he cutting edges 30 of the dogs 24 engage the upper end of the core and drill the core away. 'Ihe engagement of the upper walls of the openings 26 with the upper edges of the dogs 24. transmits the downward feed pressures from the body I0 to the dogs 24. It will be observed that the engagement of the dogs 24 with the core serves to maintain the dogs in their active cutting positions so long as the drilling operation continues. 'Ihe springs 3| assist in yieldingly holding the dogs in their active positions. Circulation fluid is pumped `down through the drilling string and discharges at the lower end of the opening and the notches 2|. Circulation fluid is also discharged through the openings 26 to carry away the cuttings from the core and to flush the dogs 24.

When asurveying instrument, sample-taker, or l other object is to be lowered into the well the rotary drilling operations are suspended and the bit may be raised from thebottom of the hole. The instrument or object is run down through the drilling string and passes through or into the opening I l. In most instances the object or tool will pass through the opening Il to protrude from the lower end of the bit. As described above, the flange I6 and the reduced lower portion of the opening centralize the surveying instrument or object and the instrument may be supported on the flange I6. When the object or instrument is moving downwardly in the opening ll its lower end contacts the faces 29 of the* dogs 24. This engagement causes the dogs 24 to move downwardly and outwardly and the downwardly moving object or instrument retracts the dogs to positions clear of the opening Il. 'I'he dogs 24 do not interfere with the movement of the surveying tool or object through theopening' Il. When the survey, test or sample has been i engagement with the dog 24B.

upwardlythrough the opening and the drilling string. Upon removal of the object or surveying instrument the springs 3| automatically shift the dogs 24 upwardly and inwardly to the active positions illustrated in the drawing conditioning the dogs 24 for further operation. The

tool may then be operated as above to continue` the drilling operations.

The form of the invention illustrated in Fig. 4 of the drawing includes a body |65 provided with a central longitudinal opening Il* adapted to receive an object or surveying instrument and carrying cutting means l2 for making an annular cut in the earth formation. The body lli'l is further provided with one or morelateral openings 26. In the case illustrated there is one lateral opening 26B. 'I'he opening 26 extends horizontally or laterally through the thick wall at the lower end part of the body I0 and is open at the outer side of the body. 'I'he opening 26* is provided to shiftabiy receive a core cutting dog 24a. The opening 26 may have fiat parallel side walls and has fiat parallel top and bottom-walls extending at substantially right angles to the longitudinal axis of the opening H. The dog 24 lower ends for bearing on the upper and lower` walls of the opening. I'he dog 24 is shiftable between a position where it projects into the opening I to cut away the core of earth formation and a position where it is retracted from the opening Il. The lower edge of the dog 24 may be bevelled or sharpened to effectively cut away the core. The upper inner corner of the dog 24 is cut away to provide a downwardly and inwardly sloping face 29a that is engageable by an object run down' through the opening Il, 'Ihe movement of the dog 24 is limited by a. pin 26* carried by the body llia and. cooperating with a horizontal slot 2l in the dog.

Spring means is provided for yieldingly holding the dog 24 in its active core cuttingposition and` for automatically restoring the dog to its active position following retraction. A A spring 3| is secured to the body I0 by a screw 32a or the like and projects into the opening 26 for The spring 3l@` is designed to `bear inwardly against the outer side of the dog 24a andis adapted to shift the dog from its retracted position to its fully active position. I i

The operation of the structure shown in Fig. 4 of the drawing is substantially the same as that of the previously described form of the invention. During the drilling operation the dog 24a projects inwardly from the opening 26 and acts on the upper end of the core to cut away the same. When an object such as a surveying instrument, or the like, is run down through the openin. its lower end contacts the face 29a and this engagement retracts the dog. The dog 24Il is retractable from the opening |In to allow the ob ject or instrument to freely pass through the opening Il". When the object or instrument is withdrawn upwardly from the opening Il the spring 2li automatically restores the dog 24u to its active core cutting position.

'Il'he form cf the invention illustrated in Fig. 5 ofthe drawing includes a body Il)b similar to the body .IBl described above. The body |||b has a central longitudinal opening ||b for handling the circulation fluid and for passing' the surveying instrument, etc. One or more downwardly and outwardly sloping lateral vopenings 26h are provided in the wall of the body lili. In the construction illustrated there is a single opening 26h. The opening 26h slopes downwardly and outwardly from the opening Ilh to the exterior of the body lill. The opening 2Gb is provided to carry a bodily shiftable core cutting dog 24.1.

The dog 24!o shiftably engages the walls of the opening `"26" to be guided by the opening. The inner end of the dog 24h is fiat and slops downwardly and inwardly. The lower side or edge of the dog t4b has a sharpened cutting edge 3illb for cutting away the core. The edge 30h slopes downwardly and outwardly. 'A pin 28b carried by the body Ill"` cooperates with a slot 21 inthe dog to limit the travel of the dog. Spring means is provided for yieldingly holding the dog 24h in itsactive core cutting position. A plug 40 is secured inthe outer part of. the opening 2Gb and a spring 8l is arranged under compression between the outer end of the dog 24h and the plug 46. The outerpart of the spring di may be set in an opening il@ in the plug to be retained in place. A port dil is provided in the plug 40 to permit the free flow of uid to and from the opening 2th. v

The core cutting means illustrated in Fig. of the drawing operates in substantially the same manner as in the previously described forms of the invention. During the drilling operations the cutting edge Zilli acts on the upper end of the core to cut away the core.

Having described only typical preferred forms andapplications of'our invention, we do not wish to be limited or restricted to the specic details herein set forth, but wish to reserve to ourselves any modifications or variations that may appear 45 to those skilled in the art, or fall within the scope pf the following claims. Having described our invention, we claim: 1. A well drilling bit comprising a body having a vertical opening adapted to receive an object passed downwardly through the bit, cutting means on the body for cutting the outer portion of the well, and a bodily shiftable cutting element carried by the body to cut the inner portion of the well and retractable from its cutting position by said object as the object moves downwardly in the bit.

2. A welldrilling bit comprising a body having a vertical opening adapted tto receive an`object passed downwardly through the bit, cutting means on the body for cutting the outer portion of the well, a cutting element for cutting the inner portion of the well and means slidably supporting the cutting element on the body to be retractable from its cutting position by said downwardlyfmoving object.

v3. A well drilling tool comprising abody having a vertical opening, cutting means on the body operable to make an'annular cut inthe earth formation leavingy a central core of earth formation, acore cutting element shiftably supported by the body to bodily shift between a position where it is inactive and a position where it cuts away Ithe corel and is engageable by an object run downv through said opening to be retracted by the object, and means for returning the cle-r When a sample taker, surveying instrument, or the like, is -run through ment to the last named position upon removal of the said object.`

4. A well drilling. tool comprising a body having a vertical opening, cutting means on the'body operable to make an annular cut in the earth -formation leaving a central core of earth formation, a core cutting element carried by the body to bodily shift between a'position where it is projected to cut away the core and where it is en` gaged by an object run down said opening to be retracted by the object, and'spring means on the body for holding the element in the projected position and yieldable to allow retraction of the element.

5. A well drilling tool comprising a body having a longitudinal opening and a lateral opening in communication with the longitudinal opening, cutting means ony the body for making an annular cut and leaving a core of earth formation, a core cutting element bodily shiftable in the lateral opening, and yieldable means urging the element to a position where it cuts away the core and is engageable and retractable by an object run down the longitudinal opening, said means being operable to return the element to its core cutting position upon removal of said object. 1

6. A well drilling tool comprising a body having a longitudinal opening and a lateral opening in communication with the longitudinal'opening, cutting means on the body for making an annular cut and leaving a core of earth formation, a core cutting element bodily shiftable in the lateral opening between an active position and a retracted positionclear of the longitudinal opening, a sloping face on the element engageable by an object run down the longitudinal opening to cause retraction of the element, and spring means for ret rning the element to its active position upon re oval of the object.

7. A well drilling tool comprising a body having' a longitudinal opening and a lateral opening in communication with the longitudinal opening, cuttingmeans on the body for making an annular cut and leaving a core of earth formation, a core cutting element bodily shiftable in the lateral opening, means guiding the element for downward and outward movement in the lateral opening, a cam face on the element engageablel by an object run down the longitudinal opening to cause downward and outward retraction of the element, and a spring carried by the body urging the element upwardly and inwardly to its active position.

8. A well drilling tool comprising a body having a longitudinal opening and a lateral opening in communication with the longitudinal opening, cutting means on the body for making an annular lcut and leaving a core of earth formation, a core cutting element bodily shiftable in the lateral opening and guided by the opening for movement between an active position where it projects into the' longitudinal opening and a retracted position clear oi theU longitudinal opening, a spring actingA on the outer end of the element to yieldingly' urge the element to the active position, anda sloping inner face on the element engageable by an object run down through the longitudinal opening to cause `retraction of the element.

9. A well drilling tool comprising a body having a longitudinal opening and a lateral opening in communication with the longitudinal opening and sloping downwardly and outwardly, cutting means on the body for making an annular cut and leaving a core of earth formation, a core cutting element guided in said lateral opening for 'lo' movement between an active core cutting position and a retracted position clear of the longi-l tudinal opening, and a spring acting on the outer side of the element to urge it to the active position.

10. A well drilling tool comprising a body having a longitudinal opening and a lateral opening in communication with the longitudinal opening and sloping downwardly and outwardly,

10 cutting means on the body for making an annular out and leaving a core of earth formation, a

core cutting element guided in said lateral opening for movement between an active core cutting position and a retracted position clear of the longitudinal opening, a downwardly and inwardly inclined inner face on the elementl engageable by an object run down the longitudinal opening to produce retracting of the element, and a spring acting on the outer side of the element to urge it to the active position.

t THOMAS A. CREIGHTON.

THOMAS E. McMAI-IAN. 

